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Modeling plasma instability with electric arc discharges

  1. Dec 12, 2015 #1
  2. jcsd
  3. Dec 12, 2015 #2


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    With a quick read of the article, it appears the interest is inducing a more controlled atmospheric discharge, i.e., lightning, such that greater protection of electrical infrastructure is achieved. The earth's atmosphere is many orders of magnitude greater density than a fusion plasma. It's not clear the advantage of this process for magnetically confined fusion systems. Perhaps the_wolfman can provide some insight.
  4. Dec 12, 2015 #3
    Interesting. I could see how lower density could affect results. Is the lower density because of technical limits to confinement? Higher density would generally be desired if possible, right?
  5. Dec 12, 2015 #4


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    The pressure of the plasma is a function of particle density, n, and the temperature, T, by virtue of P = nkT, where k is the Boltzmann constant.


    The plasma pressure is limited by the magnetic pressure and the structural materials confining the plasma. Higher density would be desirable, but we are constrained by the limits on materials.
  6. Dec 12, 2015 #5
    The laser pulse creates a partially ionized of column of gas that has a reduced density. These two effects reduce the breakdown voltage and resistivity is the column. Current takes the path of least resistance, so the laser pulse is creating a preferred path for the arc to follow.

    Magnetically confined plasmas are usually completely ionized. So its hard to imagine where this mechanism would be applicable except maybe during start up.

    It is interesting thato the arcs have such a well defined cylindrical shape.
  7. Dec 14, 2015 #6


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    As far as I know, field strength is a limitation with magnetic confinement fusion plasmas, but not structural limits of materials, not yet.
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